US2026054843A1PendingUtilityA1
Aircraft with an unducted fan propulsor
Est. expiryAug 4, 2043(~17 yrs left)· nominal 20-yr term from priority
Inventors:CARLE SARA ELIZABETHTWEEDT DANIEL LKHALID SYED ARIFBREEZE-STRINGFELLOW ANDREWBOWDEN WILLIAMWOOD TREVOR HRAMAKRISHNAN KISHORE
F05D 2300/603F05D 2240/125F05D 2240/122F05D 2240/121F05D 2220/323F02K 3/02F01D 9/041F01D 5/282F01D 5/141B64D 27/402B64D 2027/005B64D 27/18B64C 11/48B64C 3/32
71
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Claims
Abstract
The present disclosure is generally related to aircraft having one or more unducted fan propulsors at locations within specific regions relative to an airfoil, such as a wing or horizontal stabilizer. More specifically, the specific regions are located where there is a relatively higher pressure air flow beneath the wings or above a horizontal stabilizer. That higher pressure air flow can be utilized to provide increased thrust from the unducted fan propulsor.
Claims
exact text as granted — not AI-modified1 . An aircraft comprising:
a fuselage; a pair of wings extending from the fuselage, two or more unducted fan propulsors, each of the unducted fan propulsors mounted relative to one of the wings on a high pressure side thereof, the respective unducted fan propulsor having a centerline (CL), a plurality of blades arranged in a forward array and a plurality of blades arranged in a rearward array, wherein only one of the forward and rearward array of blades are rotating blades and the rotating blades define a maximum outer diameter (D), and wherein another of the forward and rearward array of blades are nonrotating blades including an outlet guide vane, the outlet guide vane including a hub portion, a tip portion, and a peak positioned between the hub portion and the tip portion in a radial direction defined by the respective unducted fan propulsor, the hub portion including a forward sweep, the tip portion including an aft sweep, wherein the outlet guide vane includes a first chord length in the tip portion, wherein the outlet guide vane includes a second chord length, and wherein a ratio of the first chord length to the second chord length is less than 0.8; a point (P) located at an intersection of the CL and a line HP perpendicular to the CL that passes through an axial midpoint between a rearward trailing edge at a root of a blade of the rearward array and a forward leading edge at a root of a blade of the forward array when the forward leading edge and rearward trailing edge of the respective blades are aligned with each other; an airfoil section having an effective quarter chord point QC; and a positioning line (R) having a length (RL) and extending from the QC to the point P of the unducted fan propulsor at an angle θ measured positive in a counter-clockwise direction when the high pressure side of the airfoil section is below the airfoil section when viewed looking from an outboard position towards an inboard position of the wing; wherein 0.07≤RL/D≤2.0 and θ is between 187° and 342°.
2 . The aircraft of claim 1 , wherein 0.15≤RL/D.
3 . The aircraft of claim 1 , wherein 0.35≤RL/D, and preferably RL/D is about 0.72.
4 . The aircraft of claim 1 , wherein θ is between 198° and 310°, and preferably between 205° and 285°.
5 . The aircraft of claim 1 , wherein the two or more unducted fan propulsors are configured to operate at a cruise flight Mach M 0 of between 0.7 and 0.9, and more preferably between 0.75 and 0.9; or the two or more unducted fan propulsors are configured to propel the aircraft at a cruise flight Mach M 0 of between 0.7 and 0.9, and more preferably between 0.75 and 0.85.
6 . The aircraft of claim 1 , wherein the unducted fan propulsor has a dimensionless cruise fan net thrust parameter expressed as follows:
0
.
1
5
>
F
net
ρ
0
A
a
n
V
0
2
>
0
.
0
6
,
wherein F net is cruise fan net thrust, ρ 0 is ambient air density, V o is cruise flight velocity, and A an is annular cross-sectional area perpendicular to an axis of rotation of a rotor axis of rotation.
7 . The aircraft of claim 1 , wherein the unducted fan propulsor is undermounted to the airfoil with one or more intermediate structures.
8 . The aircraft of claim 1 , wherein the P of the unducted fan propulsor is variable to accommodate different operating conditions.
9 . The aircraft of claim 1 , wherein the second chord length is a maximum chord length of the outlet guide vane, and wherein the hub portion includes the maximum chord length or the peak is defined at a same radius as the maximum chord length.
10 . The aircraft of claim 1 , wherein the ratio of the first chord length to the second chord length is less than or equal to 0.6.
11 . The aircraft of claim 1 , wherein the outlet guide vane further includes a leading edge and a trailing portion, wherein the leading edge is formed of a metal, wherein the trailing portion is formed of a composite material, and wherein an outer radial surface of the tip portion of the outlet guide vane includes a metal tip cap.
12 . The aircraft of claim 1 , wherein the tip portion of the outlet guide vane further includes a tip, wherein the ratio is a chord variation ratio, wherein a sweep from the peak to the tip is characterized by a leading edge sweep characteristic ratio of (i) a first distance from the peak to a leading edge of the tip in an axial direction defined by the respective unducted fan propulsor to (ii) a second distance from the peak to the tip in the radial direction, wherein the leading edge sweep characteristic ratio is greater than or equal to 0.1 and less than or equal to 1.8.
13 . The aircraft of claim 12 , wherein the leading edge sweep characteristic ratio is greater than or equal to 0.5 and less than or equal to 1.8.
14 . An aircraft, comprising:
a fuselage; an airfoil extending from the fuselage, the airfoil having an airfoil section defining an effective quarter chord point (QC); an unducted fan propulsor mounted relative to the airfoil section on a high pressure side thereof, the unducted fan propulsor having a centerline (CL), a plurality of blades arranged in a forward array and a plurality of blades arranged in a rearward array, wherein only one of the forward and rearward array of blades are rotating blades and the rotating blades define a maximum outer diameter (D), and wherein another of the forward and rearward array of blades are nonrotating blades including an outlet guide vane, the outlet guide vane including a hub portion, a tip portion, and a peak positioned between the hub portion and the tip portion in a radial direction defined by the unducted fan propulsor, the hub portion including a forward sweep, the tip portion including an aft sweep, wherein the outlet guide vane includes a first chord length in the tip portion, wherein the outlet guide vane includes a second chord length, and wherein a ratio of the first chord length to the second chord length is less than 0.8; a point (P) located at an intersection of the CL and a line HP perpendicular to the CL that passes through an axial midpoint between a rearward trailing edge at a root of a blade of the rearward array and a forward leading edge at a root of a blade of the forward array when the forward leading edge and rearward trailing edge of the respective blades are aligned with each other; and an ellipse origin positioning line (EOR) having a length (EORL) extending from the QC to an ellipse origin (OR) at an angle θ measured positive in a counter-clockwise direction when the high pressure side of the airfoil section is below the airfoil section, and measured positive in a clockwise direction when the high pressure side of the airfoil section is above the airfoil section, when viewed looking for an outboard position towards an inboard position; wherein the P of the unducted fan propulsor is located within a first ellipse having a first major axis length (1MajAL) and a first minor axis length (1MinAL) with a first ellipse origin defined by EORL/D of 0.938 and θ of 253.6°, and where 1MajAL/D is 2.8 and 1MinAL/D is 1.7.
15 . The aircraft of claim 14 , wherein the P of the unducted fan propulsor is located in a second ellipse having a second major axis length (2MajAL) and a second minor axis length (2MinAL) with a second ellipse origin defined by EORL/D of 1.051 and θ of 248.8°, and where 2MajAL/D is 1.86 and 2MinAL/D is 1.56.
16 . The aircraft of claim 14 , wherein the P of the unducted fan propulsor is located in a third ellipse having a third major axis length (3MajAL) and a third minor axis length (3MinAL) with a third ellipse origin defined by EORL/D of 0.870 and θ of 239.6°, where 3MajAL/D is 1.4 and 3MinAL/D is 0.9.
17 . The aircraft of claim 14 , wherein the P of the unducted fan propulsor is located in a fourth ellipse having a fourth major axis length (4MajAL) and a fourth minor axis length (4MinAL) with a fourth ellipse origin defined by EORL/D of 0.763 and θ of 235.7°, and where 4MajAL/D is 0.94 and 4MinAL/D is 0.44.
18 . The aircraft of claim 14 , wherein the second chord length is a maximum chord length of the outlet guide vane, and wherein the hub portion includes the maximum chord length or the peak is defined at a same radius as the maximum chord length.
19 . An aircraft, comprising:
a fuselage; an airfoil extending from the fuselage, the airfoil having an airfoil section defining an effective quarter-chord point (QC); an unducted fan propulsor mounted relative to the airfoil section on a high pressure side thereof, the unducted fan propulsor having a centerline (CL), a plurality of blades arranged in a forward array and a plurality of blades arranged in a rearward array, wherein one of the forward and rearward array of blades are rotating blades and the rotating blades define a maximum outer diameter (D), and wherein another of the forward and rearward array of blades are nonrotating blades including an outlet guide vane, the outlet guide vane including a hub portion, a tip portion, and a peak positioned between the hub portion and the tip portion in a radial direction defined by the unducted fan propulsor, the hub portion including a forward sweep, the tip portion including an aft sweep, wherein the outlet guide vane includes a first chord length in the tip portion, wherein the outlet guide vane includes a second chord length, and wherein a ratio of the first chord length to the second chord length is less than 0.8; a point (P) located at an intersection of the CL and a line HP perpendicular to the CL that passes through an axial midpoint between a rearward trailing edge at a root of a blade of the rearward array and a forward leading edge at a root of a blade of the forward array when the forward leading edge and rearward trailing edge of the respective blades are aligned with each other; and a positioning line (R) having a length (RL) and extending from the QC to the point P of the unducted fan propulsor at an angle θ measured positive in a counter-clockwise direction when the high pressure side of the airfoil section is below the airfoil section, and measured positive in a clockwise direction when the high pressure side of the airfoil section is above the airfoil section, when viewed looking from an outboard position towards an inboard position (e.g. the fuselage) OR when viewed with the LE to the left of the TE; wherein 0.065<RL/D<1.98 and θ is between 187° and 340°; and wherein RL/D and θ of the P of the unducted fan propulsor adhere to the following expressions:
R
L
D
(
(
1.4161
*
[
1
.
8
8
9
7
8
*
sin
2
(
θ
)
-
0
.
0
8
7
5
*
cos
2
(
θ
)
+
0.477
*
sin
(
θ
)
*
cos
(
θ
)
]
+
1.764
*
sin
(
θ
)
+
0.19146
*
cos
(
θ
)
)
1.96
*
sin
2
(
θ
)
+
0
.
7
2
2
5
*
cos
2
(
θ
)
>
0
and
R
L
D
(
(
1.4161
*
[
1
.
8
8
9
7
8
*
sin
2
(
θ
)
-
0
.
0
8
7
5
*
cos
2
(
θ
)
+
0.477
*
sin
(
θ
)
*
cos
(
θ
)
]
+
1.764
*
sin
(
θ
)
+
0.19146
*
cos
(
θ
)
)
1.96
*
sin
2
(
θ
)
+
0
.
7
2
2
5
*
cos
2
(
θ
)
<
0
20 . The aircraft of claim 19 , wherein the second chord length is a maximum chord length of the outlet guide vane, and wherein the hub portion includes the maximum chord length or the peak is defined at a same radius as the maximum chord length.Join the waitlist — get patent alerts
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